It's the first time pollster Abacus Data of Ottawa has found the prime minister to be so unpopular with so many Canadians.

A leader's personal unpopularity is always an issue for the party he or she leads but the Conservatives in particular have taken great pains to identify their brand closely with Harper.

"When your unfavourable rating hits 50%, that says they don't just dislike your policies, they dislike you," Abacus CEO David Coletto said. "In an era of weak partisan attachments and a fickle electorate, that's a tough number to overcome."

A year ago, about the same number of Canadians approved as disapproved of the job Harper is doing. But now, 50% of those surveyed by Abacus disapprove while 35% approve. The rest - 15% - had no opinion.

"Stephen Harper has always been a polarizing figure in Canadian politics. Canadians either like him or dislike him; there's nothing neutral about him," said Coletto.

As far as overall popular support goes, Harper's Conservatives are tied with Thomas Mulcair's NDP at 35%.

Compared to last month, that's a slight weakening for Conservatives - down two percentage points -- while NDP support strengthened somewhat - up three points - since Abacus' last poll a month ago.

Mulcair is alone among federal leaders in that more approve of the job he does (36%) than disapprove (22%).

But many more (43%) have not made up their mind about Mulcair, one reason why these first few weeks in the House of Commons are important to both Conservatives and New Democrats as they battle to convince Canadians to make up their minds about Mulcair one way or the other.

The Liberals, meanwhile, are stuck well back with 17% voter support, just below their level of popular support in the last general election.

Abacus polled 1,208 Canadians between Sept. 14-18 using an online survey. The poll participants were chosen at random from an online database of 150,000 volunteers. The pollster weighted the survey sample by age, gender, region and education level according to the most recent census data. The pollster's method is widely used and, according to the industry association of which the pollster is a member, is believed to be capable of producing accurate results.